Sökning: "NATURAL SCIENCES Physics Astronomy and astrophysics High energy astrophysics"

Visar resultat 1 - 5 av 38 avhandlingar innehållade orden NATURAL SCIENCES Physics Astronomy and astrophysics High energy astrophysics.

  1. 1. Searches for Particle Dark Matter : Dark stars, dark galaxies, dark halos and global supersymmetric fits

    Författare :Pat Scott; Joakim Edsjö; Lars Bergström; Jan Conrad; Dan Hooper; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; dark matter; supersymmetry; gamma rays; dwarf galaxies; stellar evolution; cosmological perturbations; phase transitions; statistical techniques; Astroparticle physics; Astropartikelfysik; Astroparticle physics; Astropartikelfysik; Cosmology; Kosmologi; Elementary particle physics; Elementarpartikelfysik; Computational physics; Beräkningsfysik; Formation and development of stars; Stjärnors bildning och utveckling; High energy astrophysics; Högenergiastrofysik; teoretisk fysik; Theoretical Physics;

    Sammanfattning : The identity of dark matter is one of the key outstanding problems in both particle and astrophysics. In this thesis, I describe a number of complementary searches for particle dark matter. LÄS MER

  3. 2. Extending the observational reach of core-collapse supernovae for IceCube using high-energy neutrinos

    Författare :Nora Valtonen-Mattila; Erin O'Sullivan; Timothy Linden; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Neutrino physics; Neutrino astrophysics; Supernovae; Core-collapse supernovae; Particle astrophysics; Fysik; Physics;

    Sammanfattning : Neutrino telescopes such as IceCube monitor for low-energy neutrinos O(10 MeV) produced in nuclear processes during core-collapse in supernovae. The detection horizon to the neutrino burst is 50 kpc, the distance to the Magellanic Clouds. LÄS MER

  4. 3. The Extremes of Neutrino Astronomy : From Fermi Bubbles with IceCube to Ice Studies with ARIANNA

    Författare :Elisabeth Unger; Allan Hallgren; Olga Botner; Antonio Capone; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; astroparticle physics; neutrino telescopes; IceCube; Fermi bubbles; ARIANNA; horizontal propagation; surface wave propagation; Fysik med inriktning mot elementarpartikelfysik; Physics with specialization in Elementary Particle Physics; High Energy Physics; Högenergifysik;

    Sammanfattning : The Fermi bubbles are extended regions of hard gamma-ray emission which were discovered with Fermi-LAT data to exist above and below the Galactic Center. In order to explain the origin of the gamma-rays, different theories are proposed. LÄS MER

  5. 4. A Stacked Prism Lens Concept for Next-Generation Hard X-Ray Telescopes

    Författare :Wujun Mi; Mats Danielsson; Peter Nillius; Ralf K. Heilmann; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; focusing X-ray telescopes; Wolter-I optics; stacked prism lens; focused UV lithography; grayscale e-beam lithography; proximity effect correction; angular resolution; effective collecting area; röntgenteleskop; Wolter-I-optik; staplade prismalinser; fokuserad UV-litografi; elektronstråle-litografi; Fysik; Physics;

    Sammanfattning : Over the past half century, the focusing X-ray telescope has played a very prominent role in X-ray astronomy at the frontier of fundamental physics. The finer angular resolution and increased effective area have enabled more and more exciting discoveries and detailed studies of the high-energy universe, including the cosmic X-ray background (CXB) radiation, black holes in active galactic nuclei (AGN), galaxy clusters, supernova remnants, and so on. LÄS MER

  7. 5. Laboratory and stellar spectroscopy of the complex ions Fe+, Mo+, Th+ and U+

    Författare :Hampus Nilsson; Astronomi - Genomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; molybdenum; iron; thorium; uranium.; Atomic and molecular physics; Atom- och molekylärfysik; Astronomy; space research; cosmic chemistry; Astronomi; rymdvetenskap; kosmisk kemi; Condensed matter:electronic structure; electrical; spektroskopi; magnetisk resonans; supraledare; magnetiska och optiska ; egenskaper elektriska; Kondenserade materiens egenskaper:elektronstruktur; spectroscopy; relaxation; magnetic resonance; magnetic and optical properties; supraconductors; astrophysics; radiative lifetimes; oscillator strengths; term analysis; Fourier transform spectroscopy; branching fractions; Fysicumarkivet A:2002:Nilsson;

    Sammanfattning : The new generation of high resolution astronomical instruments such as the Hubble Space Telescope (HST) or the Very Large Telescope (VLT) has renewed the demand for accurate atomic parameters like wavelengths, oscillator strengths and line profiles accompanied by reliable uncertainty estimates. Fourier transform spectroscopy has proven to be a powerful tool when measuring these parameters. LÄS MER